/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.context.support;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * 独立XMLapplication context,将文本路径解析为包含包路径的class path资源名称(e.g.
 * "mypackage/myresource.txt"),并作为context定义文件。作为测试工具，或者在JAR中嵌入的Application
 * Context很有用。<br/>
 * 
 * Standalone XML application context, taking the context definition files from
 * the class path, interpreting plain paths as class path resource names that
 * include the package path (e.g. "mypackage/myresource.txt"). Useful for test
 * harnesses as well as for application contexts embedded within JARs.
 * 
 * <p>
 * The config location defaults can be overridden via
 * {@link #getConfigLocations}, Config locations can either denote concrete
 * files like "/myfiles/context.xml" or Ant-style patterns like
 * "/myfiles/*-context.xml" (see the
 * {@link org.springframework.util.AntPathMatcher} javadoc for pattern details).
 * 
 * <p>
 * Note: In case of multiple config locations, later bean definitions will
 * override ones defined in earlier loaded files. This can be leveraged to
 * deliberately override certain bean definitions via an extra XML file.
 * 
 * <p>
 * <b>This is a simple, one-stop shop convenience ApplicationContext. Consider
 * using the {@link GenericApplicationContext} class in combination with an
 * {@link org.springframework.beans.factory.xml.XmlBeanDefinitionReader} for
 * more flexible context setup.</b>
 * 
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see #getResource
 * @see #getResourceByPath
 * @see GenericApplicationContext
 */
public class ClassPathXmlApplicationContext extends
		AbstractXmlApplicationContext {

	private Resource[] configResources;

	private String[] configLocations;

	/**
	 * Create a new ClassPathXmlApplicationContext, loading the definitions from
	 * the given XML file and automatically refreshing the context.
	 * 
	 * @param configLocation
	 *            resource location
	 * @throws BeansException
	 *             if context creation failed
	 */
	public ClassPathXmlApplicationContext(String configLocation)
			throws BeansException {
		this(new String[] { configLocation }, true, null);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext, loading the definitions from
	 * the given XML files and automatically refreshing the context.
	 * 
	 * @param configLocations
	 *            array of resource locations
	 * @throws BeansException
	 *             if context creation failed
	 */
	public ClassPathXmlApplicationContext(String[] configLocations)
			throws BeansException {
		this(configLocations, true, null);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext with the given parent,
	 * loading the definitions from the given XML files and automatically
	 * refreshing the context.
	 * 
	 * @param configLocations
	 *            array of resource locations
	 * @param parent
	 *            the parent context
	 * @throws BeansException
	 *             if context creation failed
	 */
	public ClassPathXmlApplicationContext(String[] configLocations,
			ApplicationContext parent) throws BeansException {
		this(configLocations, true, parent);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext, loading the definitions from
	 * the given XML files.
	 * 
	 * @param configLocations
	 *            array of resource locations
	 * @param refresh
	 *            whether to automatically refresh the context, loading all bean
	 *            definitions and creating all singletons. Alternatively, call
	 *            refresh manually after further configuring the context.
	 * @throws BeansException
	 *             if context creation failed
	 * @see #refresh()
	 */
	public ClassPathXmlApplicationContext(String[] configLocations,
			boolean refresh) throws BeansException {
		this(configLocations, refresh, null);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext with the given parent,
	 * loading the definitions from the given XML files.
	 * 
	 * @param configLocations
	 *            array of resource locations
	 * @param refresh
	 *            whether to automatically refresh the context, loading all bean
	 *            definitions and creating all singletons. Alternatively, call
	 *            refresh manually after further configuring the context.
	 * @param parent
	 *            the parent context
	 * @throws BeansException
	 *             if context creation failed
	 * @see #refresh()
	 */
	public ClassPathXmlApplicationContext(String[] configLocations,
			boolean refresh, ApplicationContext parent) throws BeansException {

		super(parent);
		this.configLocations = StringUtils.trimArrayElements(configLocations);
		if (refresh) {
			refresh();
		}
	}

	/**
	 * Create a new ClassPathXmlApplicationContext, loading the definitions from
	 * the given XML file and automatically refreshing the context.
	 * <p>
	 * This is a convenience method to load class path resources relative to a
	 * given Class. For full flexibility, consider using a
	 * GenericApplicationContext with an XmlBeanDefinitionReader and a
	 * ClassPathResource argument.
	 * 
	 * @param path
	 *            relative (or absolute) path within the class path
	 * @param clazz
	 *            the class to load resources with (basis for the given paths)
	 * @throws BeansException
	 *             if context creation failed
	 * @see org.springframework.core.io.ClassPathResource#ClassPathResource(String,
	 *      Class)
	 * @see org.springframework.context.support.GenericApplicationContext
	 * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader
	 */
	public ClassPathXmlApplicationContext(String path, Class clazz)
			throws BeansException {
		this(new String[] { path }, clazz);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext, loading the definitions from
	 * the given XML files and automatically refreshing the context.
	 * 
	 * @param paths
	 *            array of relative (or absolute) paths within the class path
	 * @param clazz
	 *            the class to load resources with (basis for the given paths)
	 * @throws BeansException
	 *             if context creation failed
	 * @see org.springframework.core.io.ClassPathResource#ClassPathResource(String,
	 *      Class)
	 * @see org.springframework.context.support.GenericApplicationContext
	 * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader
	 */
	public ClassPathXmlApplicationContext(String[] paths, Class clazz)
			throws BeansException {
		this(paths, clazz, null);
	}

	/**
	 * Create a new ClassPathXmlApplicationContext with the given parent,
	 * loading the definitions from the given XML files and automatically
	 * refreshing the context.
	 * 
	 * @param paths
	 *            array of relative (or absolute) paths within the class path
	 * @param clazz
	 *            the class to load resources with (basis for the given paths)
	 * @param parent
	 *            the parent context
	 * @throws BeansException
	 *             if context creation failed
	 * @see org.springframework.core.io.ClassPathResource#ClassPathResource(String,
	 *      Class)
	 * @see org.springframework.context.support.GenericApplicationContext
	 * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader
	 */
	public ClassPathXmlApplicationContext(String[] paths, Class clazz,
			ApplicationContext parent) throws BeansException {

		super(parent);
		Assert.notNull(paths, "Path array must not be null");
		Assert.notNull(clazz, "Class argument must not be null");
		this.configResources = new Resource[paths.length];
		for (int i = 0; i < paths.length; i++) {
			this.configResources[i] = new ClassPathResource(paths[i], clazz);
		}
		refresh();
	}

	protected Resource[] getConfigResources() {
		return this.configResources;
	}

	protected String[] getConfigLocations() {
		return this.configLocations;
	}

}
